Dynamometer



J. L. TAYLOR I 2,035,576

DYNAMOMETER Filed A ugL 12, 1932- 2 Sheets Sheef; 1

. a j l 518 252122 27 13 5 1, IQNVENTOR:

mr lily/am ATTORNEY.

' March 31, 1936.

J. L. TAYLOR DYNAMOMETER Filed Aug.

2 Sheets-Sheet 2 JM/i lama INVENTOR:

' ATTORNEY.

Patented Mar. 31, 1936 {UNITED STATES PATENTOFFICE Original 570,943,this application Augu 628,491

This invention relates to dynamometers, and more particularly to thosein which energy is absorbed and torque measured by means of a fluidbrake, and an object of the invention is to generally improve theconstruction and operation of such mechanism, and to broaden the fieldof usefulness thereof.

More particularly, an object of the invention is to provide a fluidbrake construction capable of resisting rotation'in either directionwith substantially equal efficiency.

A further object is to provide such a structure which cari be extremelyclosely regulated, and further objects are to provide e following:

Such a structure having a urality of rotors in separate chambers, andmeans for permitting flow selectively into the individual chambers;

Such a structure which provides for a relatively large capacity; I

Such a structure in which the forms of the rotor and stator are such asto cause a transfer of masses of fluid alternately from the one to theother during operation of the device;

Such a structure in which the fluid engaging elements comprise pocketsor openings characterized by curved surfaces adapted to so direct thefluid;

A form for such pockets or openings which will cause a relatively smoothtransfer of fluid anqd An arrangement of stator and rotor elementsarranged to operate together without substantial clearance, and in whichthe how of fluid in the device is necessarily substantially entirelywithin the openings of the elements "Such a structure in which paths areprovided for inward movement 01 fluid displaced from fluid. pocketssuitable which it tends the order shown,

application October 24, 1931, sen-mine.

now Patent No.

1,991,826. Divided and st 12, 1932, Serial No.

29 Claims. (cl. 188-90) adapted to be employed as a dynamometer assembly.

Fig. 2 is an enlarged top plan, broken away to disclose interioraspects. k I

Fig. 3 is a sectional view taken on line 3-8 of Fig. 1. Fig. 4 is asection view taken on line 4-4 of Fig. 2. I Fig. 5 is a sectional viewtaken on line 5-5-01 Fig. 4. Fig. 6 is a sectional view taken on line 64of Fig. 4.

Fig. 7 is a perspective view of spacing collars. employed herein.

,Fig. 8 is a perspective,view oia thrust washer. Fig. 9 is a perspectiveview ofa shattbushing. Fig. 10 is a perspective view of the axial shafthere employed showing parts broken away.

Fig. 11 is a vertical axial section of a modified bearing arrangement.

Fig. '12 is a perspective view of plo'yed in the structure. oi Fig. 11.

Fig. 13 is a plan view, partly in section, of a hydraulic onmodification involving principles of the invention.

Similar reference characters apply to like parts in all the flgln'esaforesaid. Refen'ing to Fig. '1, the machine comprises generally-a fluid.brake A carried ona shaft C with to rotate when energy from therotating shaft is absorbed in the brake. An arm U extends from brake Aand prevents rotation thereof, the force necessary to do this beingmeasured by a scale or weighing mechanism G forming the subject matterof my co-pending application, 85. Serial No. 570,943, filed October 24,1931, of which 20 an element emthis application is a division. Brake Acomprises similar heads B, mounted upon shaft 0,. the membly beingsupported in joumalingstandards D. Betweenheads .Bare clamped, generallyin 40 stator discs-E Fig. 5.which are separated from each'other byspacer rings F, the joints sotormed by headsB, discsE, and spacer rings1?, beingsealed by appropriate gaskets orotherwellknownmeanssuchasfllmsofshellw like products between the opposedfaces of the elements, the same being drawn igh y togetherby suitablebolt and nut or other means, H, to form a integral unit sealed instfluid le atsaid joints. The heads 3 have hollownsB'whichareboredandnl'el'erstator disks E by spacing-collars L whichare ar- 4 ments M, the latter being conveniently formed as integralparts of the heads B. The said collars also have wearing faces L,whichtog'ether-with the bores of elements M are of suitable bearingmateriali The exact positioning of the rotor element to give the correctrunning clearance beranged to approrimately fill the spaces remainingbetween the end disks and suitable thrust eletween the rotor and statordisks may conveniently be determined by thrust washers N-disposed be.-tween the faces L and M. The assembly upon the shaft C. wlllbepositively held a n t longitudinal movement relatively to the shaft inthe present instance by athreaded collar or nut element L engaging athread 1. on said shaft, the nut being prevented from loosening by a setscrew L or other well known means. The shaft C is provided with ashoulder against which the discs K are clamped by not L, the generalaspect of the shaft being shown in Fig. 10. I h

The outer peripheries of the trunnions 3' form the inner raceways forroller-bearings P and the outer raceways for said rollers areprovided bythe hubs D of the standards D, the latter being attached to anysuitablebase, or the purposes of the standards may be served by otheradjacent structure if such is available. The rollers P are confined totheir annular raceways by means of annular end, or ring-plates d.

The operating medium for the dynamometer unit A may be any suitablefluid supplied by an appropriate line Q, and, in a like manner,discharged through R. The fluid will find its way. between the rotor andstator elements from inlet Q to outlet R, by means of manifold elementsto be later described. 4 The heads B and disks E with complementaryraised surfaces which-approach as shown so as to provide substantiallyonly mechanical clearance between the station- 50 ary and rotatingelements, and the heads B are provided with pockets or openings I, l',and I". The rotor disks K have peripheral fins 2, Fig, 4 which arespaced from and opposed to similar fins 3 inwardly projecting from thering spacers F. Both faces of the disks E and K are provided withrecesses or openings 4. i, and 6, I, mpectively while the aforesaid fins2 and 3 provide opposed peripheral recesses I and 9. The portions of thedisks remaining between the openings form lands or ribs r between theopenings, the lands of adjacent disks approaching each other so closelyas to substantially prevent any flow offluid between the disks excep'tbyway of the openings 5, G, I, 1, etc. 5 In the present instance there are25 ribs of the recesses l opposed to 24 ribs of the recesses I, and 50ribs of the recesses 5, similarly opposing 49 ..ribs of the recesses I,the rib-enclosed recesses of the heads B-being similar to the divisionsin the 70 stator discs E. In like mannerthe number of ribs 2 on theperiphery of the disks is different,

. although preferably only slightly, from the number of ribs 3 on therings Has-clearly shown in Fig. 4, wherein the ribs 2 are shownregistering 745 with the ribs 3 immediately above the brake shoe and Kare provided It, while the ribs 2 are somewhat displaced from the ribs 3immediately below the brake shoe. This difference in the number ofrecesses on adjacent disks preventsregistration of all the recesses ofthe disks with each other at one time, thus preventing the development0! a different torque at these points than would occur at points 4 ofnon-registration, and preventing any. ripple' in the torque opposed to adriving means under test, or. vibration inthe dyrfamometer itself. Thestator openings ferent radial extent than the rotor openings 6 and I,and this further reduces the tendency to vibration and facilitates-thetransfer of fluid from rotor to stator and back, as more fully describedbelow.

4 and 5, are preferably of dif- The operation of this general type offluid brake is wellknown, the fluid, more or less filling the recesseson the opposed disks, being energy from the rotating disks,'anddissipating it in the form of heat when it encounters the ribs on thestationarydisks, the fluid tending to turn given kinetic thestationaryliisks and thus generating a torque therein which is equal tothat with which it opposes the rotation of the rotating disks, and whichmay be measured by scale G.

.The journaling of the shaft C will preferably 'be lubricated with thefiuid employed in operatfind its way through the bearing journals bymeans of grooves N formed in the thrust wash-.-

ers N the fluid being tra tted as a film along ing therefrom/to anyconvenient waste receptacle. The bores for the bushings J will be sealedby an appropriate packing T. which will have a follower ring T. A collarS fitting loosely around the shaft C is engaged by a compression spring3 that surrounds the shaft between the collar 8 andthe ring T toresiliently urge the ring in a direction to compress the packing. Thesaid collar can be taken up by suitable screws s engaged in the presentinstancewith trunnions B. Collar S is originally set to compress thespring S for a desired pressure, and may be again adjusted ing theinvention. From the recesses I, fluid will I when necessary, which willbe rarely. The said dynamometer, so that the friction of the roller-.

bearings P,will be a minor consideration, readily cared for by any ofthe simpler lubricating devices already well-known.

'Fig. 6 illustrates the theory of operation of the disclosed fiuidbrake. As shown in the figure the pockets 5 and 6 at the instant are inopposed relation, such that they form a cavity that is in cross sectionan approximation of a flattened oval. The figure indicates an actionwhich takes place during the overlapping of the ribs at the joints Xa. Avolume of fiuid, indicated by plain arrows, is carried at a certainvelocity by the rotor K, which is'turning in the direction indicated bythe feathered arrow, and by virtue of the curvature .at the wall X1) inpocket 6, is thrown diagonally against the wall Xc of pocket 5,dissipating the energy of -motion which it has acquired from K in'itsimpact against the stator E, the impact developing a force tending tomove the stator E in the same direction as the in the stator openings,

. the rotor openings by rotor K, the similar but reverse curvature ofthe wall Xc deflecting said volume back to the rotor pocket 6 where itagain picks up velocity to rethe least possible tendency to form eddies,spray,'

emulsion or the like. f

It is also to be noted that fluid in the openings. 6 and 'l of the rotordisks will have a radial component of force due to the centrifugaleffect of the rotation of the disks, while that in openings 4 and 5 ofthe stator disks will not. There will therefore be a flow of fluidoutwardly of the openings of the rotor,- this fluid being deflectedlaterally by the outer walls of the openings into the adjacent openingsin the stator. Fluid already being under no centrifugal force, is'displaced backwardly toward the axis of the disks, and finally directedback into the inner ends of the stator openings, the pressure in therotor openings at this point being less than that nearer the peripheryof the disk because of theshorter radius of the path of movement ofthisfiuid. Under conditions where the openings are only partly filled,these portions of the rotor openings may be entirely empty except forthe fluid being. introduced from the stator openings.

Suitable fluid control valves, inlet l and discharge ll, Fig. 1 controlthe fluid on its way to and from appropriate manifolds l2 and I 3 whichare attached to the periphery of the unit A so as running somecompartments to lie in communication with ports i4 Fig. 5 in the spacerrings F registering with the spaces between statoi disks E. The spacerrings F- of the brake are provided with outlet ports at their lowerportions corresponding to inlet ports M. In the manifold l2 closurevalves 14' are provided which may be used in certain instances where arestricting of the ports i4 may be desirable, or where, for exampleunder light load, better graduation of resistance can be accomplished byempty and taking certain of valves i4 the load on those remaining, thenbeing, entirely closed.

For permitting exceptionally flne graduation of the fluid supply aby-pass i5 that is controlled by a relatively smaller valve I6 isprovided. The bypass arrangement provides an economical method ofobtaining an inlet means with ordinary elements which will be variableaccurately over a by suitable setting of valves IO, H, H,

This eifect is obtained by partly closing the valve wide range ofcapacities. -A suitable fitting at the manifold i2 will permit ofattaching an appropriate pressure gauge V and a check-valve II, thelatter serving to admit air to the assembly A when it is desired toempty it when at rest.

During operation the liquid forms a vortex: withinthe assembly and theradial depth of the liquid of this formationmay be regula ed andmaintained in accordance with the desired effect and I6.

Ii so as to restrict the device and cause the vortex the discharge offluid from an accumulation of fluid in suflicient so that the pressuredevelto any specific curve The oped by the centrifugal action thereofwill cause a discharge equal to the inflow through manifold l2. Themanifold is will be similar tothe one just described except thatthevalves Hf under most conditions will not be used at the fluid dischargeside. The valve ll also admits air when 'it'is desired to reduce theliquid content of the device when in operation, the liquid dischargingat manifold i3 until the internal pressure at manifold .12 due tocentrifugal force becomes less than atmospheric, when the valve opens,admitting air, which mixes with the liquid and finds its way to thecenter of the vortex within the machine. In the outflow line R provisionis arranged for a thermometer Z preferably located between the manifoldl3 and discharge valve i l.

The dynamometer will operate in conjunction with a suitable scalesuit-ably suspended independently of the dynamometer and aifected by avertical staff U, instance with above mentioned beam U, carried by thedynamometer assembly. Since this scale feature is set forth in detail inmy co-pending application filed Oct. 24, 1931, Serial No. 570,943,patented February 19, 1935, Patent No. 1,991,826, the same being theoriginal applica tion from which this application was divided, furtherdescripti n of it is not given herein.

To obtain increased torque for satisfactory readings for testing at lowspeeds, such for example as when starting an engine test, a frictionbraking arrangement is provided, brake-shoes l8 being movable tofrictionally contact the rotors whendesired. The shoes are arranged toretract in the present instance when not in use within recesses formedin the rings F opposite their respective rotors. Each shoe has studs H!which pass through said rings, the bores therefor being packed by meansof suitable gland-nuts or the like 20. The rods are united forsimultaneous actuation by plates 2i which in turn are transverselyunited by a crosshead 22 common to the several brake sets, and plates 2|Brake releasing springs 23 operate between nuts 23 and plates 2|. Thebrake-sets are adjusted as a single assembly by means of a threaded rod24 or the like, the manipulation of which through .arms 21 that extendfrom the assembly A. The

said rod 24 passes freely through the transverse bar 22, and acushioning spring 28 envelopes said' rod between the bar and a collarfixed on said rod, movement of the rod accordingly compressing spring28,- a direction to apply the brake. Thisarrangement tends to eliminatechatter or vibration when the brake is applied. The brake assembly. maywithdrawn from rotor contact at any time by manipulation of hand wheel25, as fol-examplewhen the unit under test is operating at high speedwhen. the friction brake will not be required. v

The mounting of said I means of a supporting bar 29 provided withterminal flats 29" which are slidable in slots formed a flat spot on thebar 29. It is understood that that is fixed in the present jcounterweight is by and urging crosshead" 22 in are the similar butlonger forms,

- relieved to, clear the 1 but practical in its general arrangement.

' the bearing Da, and

4 other counterweight means are contemplated as within the scope of theinvention.

The modification disclosed in Fig. 11 will employ rollersPa of shorterlengths, disposed as with respect to their where a suitable annularnions diameter will provide an enclosing raceway, which will belubricated through the bore 0 8.. Fluid, and spent lubricating materialwill find their way along the shaft to an annular groove 49 whichcommunicates with a passage I that leads to an on let 3, the latterbeing-oversize to preserve registry throughout the limited movement ofthe trunnions. The trunnion Ba is further counterbored to admit ananti-friction bearing 5i. Axially of the bearing ii is placed a washer'5| which is held in place-by the outer race of the bearing, the washerbeing inner race. This washer is a thrust-plate for holding a spring sofree of said inner race. The shaft Cd is threaded beyond said bearing toaccommodate turn is locked in place by aother well known means. e Theshaft Cu is suitably packed by appropriate sealing material Ta which isdivided in the present instance by an oil-ring ,the an annular groove55, Fig. 12 from which extend ports 58 through which lubricant from acontainer inserted at The said packing is provided with a follower-ringTa',held against the packing by the spring So confined between saidpacking and the aforesaid ring 51'. The assembly Just described,is'sealed against outside conditions by a cap do having a seal of simpledesign da. The volume of fluid lock washer if or discharging at :s willindicate the effectiveness of the packing Ta, which may be furthercompressed by inserting a washer in the bore behind the spring so or byinstalling additional packing.

.The trunnion bearing disclosed in Figs. 11 and 4 12 is appropriate forhigh-speed operation where frictional heat might beexcessive in thebushing structure above. disclosed, the latter being, of course, a moreeconomical arrangement.

In Fig. 13 is shown a modification wherein the elements above disclosedare adapted to a form of hydraulic power-transmission. The structure of.said. modification is intentionally; schematic,

The assembly Ad is inclosed in a stationary housing Ab within which itrotates by virtue of the exterior and aligned bearings Do and Db.

55 The power, or driving, shaft Ca terminates in a suitable pilotbearing 3. A tends from a head on Bb, ex-

4e41, arranged in sleeved relationship to rewill be appropriately sealedagainst leakage at the inner tube '31., The tube 31 will terminate witha'fluid-tight flexibleunion, not shown here,

suitable typei. The shaft withthe said tube .31. the

but of well known or Cu is bored in registry bores'branch'ing, off toprovide fluid inlet and outlet means in assembly Ac, indicated by. theresp ctive "feathered and plainarrows in Fi 13.

70 The disc and ring elements, here designated as Ed, Ea and E! F shown,and

.Ko, correspond'in general. a; the and-K, described above; The as- 'Hacircumferentially dis- 75 posed and siidable in hlignedapertures in eleaosasve above set forth, hub Da and trunnion Ba;

reduction of the truna nut 52 that in latter having 51 will flnd'its wayto the shaft.

' members with trunnion Be, the saidtrunnionbeing axially bored toreceive suitable tubeinembers,

tate with the trunnion The outer tube It again betweenltself and.

. tested to cause effectively cooled by is held together by the axialmeans brro ments as, no, and Fa whereby to permit axial relativemovement of thereof.

The abutting relations p of the members Ea and F0 is not fixed as in thedynamometer, but the members are accurately formed to abut in a fluidsealing relation, while being free to part -at their joints forallowing, the escape of fluid about the periphery, the discharged fluidflndthe parts while preventing, relative rotation or other undesiredmovement ing its way to a lower part of the housing Ab to of a drain 38,to any convenient storage reservoir; The assembly Ad is normally held inits compacted relation by the co -actlon of a spring 39 and a ring ill,the latter being connected to any appropriate controlling means whichmight conveniently take the form of a governor responsive to a powertake-off shaft ll, the latter being connected with mechanism actuated bythe said assembly. The said governor means might for example function tomodify the rotative force applied through the assembly to shaft ll inconsonance with the working resistance met by the said mechanism. Ringll is actuated by a fork l2, fulcrumed to the housing Ab, and a suitablerod 43 which latter would lead to the control or governor.

The dotted position indicates the maximum Lcontemplated separation ofthe elements comprising the assembly Aa. Themovements of r 43 will causea variable separation between the disc elements, which will vary theclearance between the driving and driven n cordingly change the amountof torque de; veloped in the driven elements. The rotors Ka must beslidably eyed to the shaft Cu, to perinit the separa on of theelementsdisclosed above, and in one instance the adiacent disc Ka' willbe flanged about an interior boss on the 'head Ba to preservei alignmentof the outer base elements and ac- Obviously maximum movement of theelements a toward each other will result in actual frictional contacttherebetween after which a direct, or

. substantially positive drive may be transmitted through the devicefrom shaft Ca to shaft 4|. The said shaft is urged in a direction topreserve a leak-tight joint at its abutment by means of a spring 44opposed to ashoulder l5 axially fixed with shaft Ca.

46, fixed with the. head Ba,- the gear meshing with a similar gear,"fixed to the power take-oi! Rotation of the driven ele-' ments istransmitted to shaft 4| through a gear substantial torque when operatingat relatively high speeds, thetorque is relatively slight, and it isthese conditions to get an the value thereof, and alsoto developsufilcient resistance to the movement. of the unit being developed atlow speeds at such speeds. The addition of the brake shoes is arrangedto contact the rotors K provides a often difficult under accuratereading of it to develop its maximum power under these conditions. Apeculiar advantage of the construction used resides 'in the fact thatthe brake shoes are the fluid normally present in the-stator, and nofurther provision is necessary for cooling the shoes even in the event.of long runs at low speed. a A e A further advantage of thearrangementarises from the combination of the two types of 'brak or the frictionbrake in; resistance in the one device. Thus it is possible to develop afixed resistance, for example at low speed, with the friction shoes, andthen to vary the total resistance in extremely attenuated increments bymerely admitting more vor less fluid to the stator chambers, the coolingeffect remain! ing substantially constant due to the fact that under anyconditions such as will result in a fluid resistance to rotation, theamount of fluid present in the chambers will be greatly in excess of theamount needed to cool the shoes.

In the modification shown in Fig. 13 the efiect is obtained by utilizingthe actual frictional contact between stator elements themselves.

The above being a complete description of illusrotor, fluid supply meansarranged to introduce fiuid'between said elements whereby to provide afluid resistance to rotation of said rotor, and a friction receivingpockets brake carried by said stator element, and manu ally controlledmeans for moving said brake when desired into frictional contact withthe other element. v

2. In a dynamometer the combination of a stator element and a rotorelement arranged to be connected with a power source to be tested, a

in a circumferential series, and a plurality of fluid pockets on saidrotor arranged in a similar series, and disposed to open into thepockets on said stator, there being an odd number of pockets statorelement including a disk having a plurality of annular series of fluidpockets on a face there-- I of, a. rotor arranged to be connected with apower source to be tested, and including a disk rotatably arranged inproximity to the above men tioned sta or disk, and having-a completeregistration of the pockets of one disk with those of the other.

means exteriorly of shoe, a

5. In a fluid actuated force controlling device the combination of astator including a pair of plurality of disks having fluid therein, aplurality of spacing rings disposed'between said end plates and ad-Jacent disks, and between adjacent disks, and

the rotor and valve elements pockets on said stator arranged said shaftextends,

collectively forming an outer shell for said stator. arotor including ashaft, a plurality said shaft and interspersed between the disks of saidstator, means fixing said disks non-rotatively but axially movably onsaid shaft, means preventing'rotative relative movement between thedisks and end plates of said stator, but permitting. axial relativemovement therebetween means for introducing a fluid between the severaldisks, and means for axially compressing the disks of said rotor andsaid stator, and regulat ing the escape of fluid between said rings andthe disks of said stator.

6. In a dynamometer. the combination of a stator having a. plurality ofchambers therein, a rotor element in each chamber, and means forsupplying fluid to said chambers including a manifold positioned tocommunicate with all said chambers, a fluid passage and a plurality ofassociated with said manifold, each valve element being positioned andarranged to control the flowof fluid into one of said chambers.

7. In a dynamometer the combination of a rotor and a stator arranged toprovide fluid spaces therebetween, and means for supplying fluid theretoincluding a fluid supply pipe, and a valve arranged to control the flowof fluid into said spaces, and a bypass connected about said valveextremely small increments.

8. In a dynamometer having a stator and a rotor cooperating therewith,the combination of a trunnion fixed with said stator, a bearing forsupporting said trunnion, and in which said .trunnion is journaled foroscillating movea shaft for said rotor, said truning material about saidshaft.

9. In a dynamometer having a stator and a rotor cooperatingtherewith, atrunnion fixed bearing means in said bore in w on said shaft issupported for rotation, a plurality of packing rings disposed about saidshaft between adjacent packing rings. men and said said trunring havingintercommunicating passagesthrough which lubricant may be introduced tosaid shaft, and said trunnion having a drain passage leading'out of saidbore between said packing rings and said bearing means, and

a resilient element arranged to continuously and yieldingly compresssaid packing rings about said shaft. I

10. In a dynamometer. the combination of a stator having a fluid chambertherein, and a rotor including a disk rotatively mounted in saidchamber, said disk and said-chamber being provided with fluid engagingelements including a plurality of pockets on said disk, means formaintaining a body of fluid in said chamber to resist rotation of saiddisk therein by engagement with oi'diskson disk with 12. In adynamometer the combination of a circumferentialseries, the number ofpockets on said side being different from the number on said periphery,a plurality of fluid pockets in said stator disposed to-open into thepockets on thea plurality of fluid ed to cooperate with periphery ofsaid disk, and pockets in said stator di the pockets on her of pocketseach case from the side of said disk, the numthe number of pockets onsaid which the stator pockets cooperate.

dynamometer shaft, means forapplyi s a fluid resistance to rotation ofsaid shaft I fluid holding casingjand a rotor withirr said casing, andmeans within said casing exposed to the cooling action of the fluid insaid casing for applying a frictional resistance to rotation of saidshaft whereby said means may be used either separately or togetheraccording to the type of resistance desired. i

13. In a dynamometer the combination of a dynamometer shaft, means forapplying a fluid resistance to rotation of sai shaft including a casingand a rotor within, "casing, and means within said casing for'appl g africtional resistance torotation" of said means maybe used eitherseparately or together, said means being arranged to furnishsubstantially equal resistance to rotation'of said shaft in eitherdirection.

14. In a'dynamometer having a stator and arotor cooperating therewith,the combination of a trunnion flxed'with said supporting said trunnion,and in which said trunnion is journaled for oscillating movement, ashaft for said rote v axial here into which said shaft extends, a bush-'ingin saidborehavingaborein -ing for lubricating p resilient element 16In a dynamometer the combination of which saitgfiiait is iourn'aled, andhaving duct means ugh which fluid from said stator may entersaid-bushand packing material disposed about 'said shaft, outwardly ofsaid bushing to prevent theescape of fluid about said shaft and throughsaid trunnion, and a V supported from saidtrunnion and arranged toyieldingly and continuously compress said packing material about saidshaft.

15. In a dynamometer the stator having a fluid chamber therein. and arotor member including a-disk rotatively mounted in said chamberisalddisk and said chamber being provided with fluid I of fluid in saidchamber to resist rotation of said disk therein by engagement with saidelements. and-a brake shoe member movable to frictionally engage saidrotor member,--one of said members being provided wuitils a a fluidchamber therein, and a stator having a disk rotatively mounted in saidrotor uding chamber, said disk having a plurality of fluid pockets insaid stator being different in e wallscurving from including a surfaces,the surfaces of one element approaching shaft whereby said elements topositions stator, a bearing for.

said trunnion having an" I brake element in combination of a en aginelements, means .te'rn'ate stator and rotor disks and p v din 1 theseveral ports stator comprisinga series of i and means providing rotorchambers between said series of fluid pocket! on the periphery thereof,and being also provided with a series of fluid, pockets and said statorproviding a series of fluid pockets,

arranged to open into the pockets on said pe- I and another series ofpockets arranged to in ery. open into the pockets on said'side, thenumber of pockets on said rotor, however, being slightly different fromthe number in said stator whereby to prevent the simultaneous openinginto each other of any substantial number of pockets of said rotor andstator.

17. A fluid brake having a stator element and a rotor element arrangedfor relative rotation, one of said elementiproviding a plurality ofopenings, and the other element-providing a plurality of axiallydirected and peripherally opposed surfaces approaching relativelyclosely to the other element during such movement, said surfacesdefining openings therebetween communicating with the openings of theother element as said movement progresses, said openings being boundedby spaced points in a plane substantiallymormal .to the axis of saidelement to positions in planes substantially parallel'to the 'axis ofsaid elemen -18. A fluid brake having. a stator element and a rotorelementarranged for relative rotation,- and each providing a pluralityof complementary very closely to those of the other element duringrotation so as to provide only necessary cal clearance therebetween, andsaid elements providing a plurality ofaxiallydirected and peripherallyopposed surfaces defining openings in of ,one element com-z saidelements, the openings municating with the openings of the other ele--ment as rotation occur said openings being bounded by walls curving fromspaced points in a plane substantially normal to the axes of said inplanes substantiallypar said elements, whereby to allel to the axes ofon a side thereof.

mechani- I provide an-easement for fluid from the openings of the otherelein a-body of fluid of one element to the openings ment to avoid undueturbulence between said elements.

19. In a dynamometer the 'combination'of a stator element and a rotorelement arranged'to be connected witz a power source to be tested, aplurality of s bstantially symmetrical fluid openings on' said stator,and a plurality of substantially symmetrical fluid openings on saidrotor arranged so as .to communicate with the openings on said stator-assaid rotor rotates, means for maintaining a body of fluid between saidrotorand stator to engage said openings and resist rotation of saidrotor, and a friction said statorand to rotation thereof regardlessofthe direction of rotation of said rotorfthe symmetrical shape of saidpockets causing equal rotation upon rotation of said rotor in either 20;In ,a dynamometer the combination of al-,'

spacing means rotor chambers between said disks, said chambers providingfluid ports communicatin therewith, and a fluid with said fluidports,and valve means controlling and including closure elementsindividual to v ipo tsm; h 2l.In' adynamome'ter the combination of aalternate stator disks,

arranged to and to offer equal resistance manifold communicating:ventingsaidstato outlet ports.

25. In a dynamometer the combination of a stator disk and a rotor diskarranged to be connected with a power source to be tested and having aface portion arranged to rotate in proximity to a race portion of saidstator, the face of one of said elements being formed to provide aseries of distributed openings, and theiace of the other element beingformed to provide a similar series of openings of one element beingpositioned to communicate with those of the other during such rotation,but some 01' said openings being substantially radially oii'settherefromto prevent registration 01' the openings of one element withthose of the other.

26. In a dynamometer the combination ot a stator disk oi-rotation ofsaid ne element overlapping those oi eat so as toprovide a tortuouspath, partly in plates and a series of alterrotor chambers therebetween,

' the openings oi said =fluidfrom said rotor,

said rotor and partly in said stator, through which alone. fluid mayflow. i

and rotor'disks, said rotor disks being arranged to be coupled to apower source to be tested, said rotor and stator disks havingcomplementary surfaces disposed for relative movement with sub!stantially only mechanical clearance during rotationof said rotor,distributed series of openings in saidv surfaces distributed openings,plementary surfaces overlapping and providing paths in said stator disksfor displacement toward the axis oi said rotor of fluid in the openingsof said stator disks, when displaced by fluid from rotor disks urgedfromthe rotor openings to the stator openings by centrifugal iorce developedby rotation of said rotor.

28. In a dynamometer a series of alternate stator and rotor disks, saidrotor disks being arranged to be coupled to a power source to be tested,said rotor and stator disks having complethe openings in said rotor uponpredetermined movement toward said axis.

29. In a dynamometer a stator and a rotor element, said rotor elementarranged to be driven from tributed openings, mentary suri'acesoverlapping and providing paths in said stator element for displacementof fluid in the openings in said said rotor when displaced bycentrifugally urged state! toward the axis of- 27. In a dynamometer aseries 01' alternate stator

